Midlevel Dental Providers Found Effective in Treating Caries

Midlevel dental providers can treat caries at least as effectively as dentists, according to a new literature review published in the January issue of the Journal of the American Dental Association.

The reviewers initially identified 7701 articles about dental therapists, dental nurses, and other practitioners with a scope of duty between that of a dentist and that of a hygienist. However, after further assessment, only 18 studies met the inclusion and exclusion criteria for the review.

On the basis of those studies, the reviewers conclude there is not enough evidence to show whether midlevel providers are more cost-effective in treating the disease.

They also conclude that midlevel providers are no more effective (but no less effective) than dentists at preventing caries — a finding touted by the ADA.

Most of the studies come from small villages far from metropolitan areas, many of them inhabited by indigenous people in New Zealand, Canada, Australia, or Alaska, who have high rates of dental disease and little access to dentists, first author J. Timothy Wright, DDS, told Medscape Medical News.

"If you put [midlevel providers] in there, untreated decay goes down and fillings go up," said Dr. Wright, chair of pediatric dentistry at the University of North Carolina in Chapel Hill.

Proposals to license midlevel providers have stirred controversy across the United States, with the ADA and many other groups of dentists opposing them and some public health advocacy groups, such as the Pew Center on the States, supporting them.

So far, midlevel providers are practicing in only 2 states: Alaska and Minnesota. However, many other countries around the world have licensed similar practitioners.

The ADA's Council on Scientific Affairs initiated the review, and several authors were officers of the ADA. The Council on Scientific Affairs, in consultation with other ADA councils, charged a research team with answering this question: "In populations where nondentists conduct diagnostic, treatment planning, and/or irreversible/surgical dental procedures, is there a change in disease increment, untreated dental disease, and/or cost-effectiveness of dental care?"

They looked at the following outcomes:

caries incidence: the proportion of people in a population who had no disease at baseline but who developed at least a single caries lesion in a specified interval;

caries increment: a count of new decayed, missing, or filled teeth or tooth surfaces (DMFT/S) in a specified interval;

caries severity: the number of DMFT/S in an individual at a given time;

caries prevalence: the number of people with at least a single caries lesion at a specific point in time; and

cost-effectiveness: the total cost of saving a single DMFT/S during a specified period.

The researchers screened the 13 databases, looking for studies that compared populations receiving irreversible care from midlevel providers with populations receiving no care or populations receiving care from dentists. They also looked for studies comparing populations before and after getting treatment from midlevel providers.

The 18 studies ultimately included in the review come from Australia, Canada, Hong Kong, New Zealand, and the United States. However, the reviewers note that 15 of these were at "high risk of bias" because of weaknesses in the study design, and the overall quality of the research was poor.. None of the studies were randomized controlled trials evaluating health outcomes or cost-effectiveness.

The studies were so different from each other that the researchers could not combine them or reach conclusions about statistical significance. The researchers found "no data" regarding diseases other than caries, such as periodontitis. Nor did they find any data about adverse events.

However, the reviewers did reach the following conclusions about select groups who received irreversible dental treatment by teams that included midlevel providers:

caries increment and severity decreased across time,

untreated caries decreased across time,

there was no difference in caries increment and severity compared with populations in which dentists provided all irreversible treatment, and

there was less untreated caries compared with populations in which dentists provided all irreversible treatment.

Dr. Wright said it is hard to reach any decisions about policies regarding midlevel providers on the basis of these data.

Cost-Effectiveness Unclear

Even though midlevel providers are reimbursed at lower rates than dentists, it is hard to compare their cost-effectiveness, he said. Setting them up in sparsely populated places requires investing in infrastructure such as suction machines and dental chairs. The typical alternative is to fly in a dentist with equipment for an occasional visit. No one has calculated which approach costs more.

He also argued that the most cost-effective way of reducing dental disease is through prevention and suggested that money spent training midlevel providers to do surgical procedures might better be spent on community dental health coordinators, a new model of practitioner advocated by the ADA. These coordinators are not trained to place fillings or extract teeth. Instead, they focus on preventive procedures, oral health education, and helping patients get to dentists.

The study's overall findings were not surprising, according to Robert J. Collins, DMD, MPH, a clinical professor of dental medicine at the University of Pennsylvania in Philadelphia. "There was nothing new in the article," he told Medscape Medical News.

However, Dr. Collins said he was disappointed with the way the ADA presented news of the study. In a news release, the organization used the headline "ADA Scientific Study Finds Surgical Midlevel Providers Do Not Reduce Overall Rates of Dental Decay," which seemed to imply that the study had found midlevel providers ineffective.

Midlevel providers have mostly been recommended as a lower-cost alternative to treating decay, not preventing it, he said. "My irritation is with the decades-long obsession the ADA has had with this issue."

Dr. Wright and Dr. Collins have disclosed no relevant financial relationships. Full conflict-of-interest information is available on the journal's Web site.